That is the highest level since the week of Nov. 15, when 30-year rates also averaged 6.24 percent. It marked a significant reversal from the beginning of the year when 30-year rates dropped below 6 percent for six straight weeks, reflecting a significant slowdown in the economy.

That slowdown prompted the Federal Reserve to aggressively cut the short-term interest rate it controls by 1.25 percentage points in January, the biggest one-month cut in the rate by the Fed in more than a quarter of a century.

While Federal Reserve Chairman Ben Bernanke again signaled during congressional testimony this week that the Fed was prepared to cut rates further in an effort to stave off a recession, investors have grown concerned about what inflation might do to their bond investments.

The government has reported that consumer and wholesale inflation jumped sharply in January.

The inflation worries have helped push up mortgage rates which are set in bond markets.

Frank Nothaft, chief economist at Freddie Mac, said the rise in mortgage rates would likely put a damper on the recent surge in mortgage refinancings.

In other rate moves this week, rates on 15-year mortgages, a popular choice for refinancing, rose to 5.72 percent, up from 5.64 percent. Rates on five-year adjustable-rate mortgages rose to 5.43 percent, up from 5.37 percent.